Variable load brake



E. S. COOK VARIABLE LOADl BRAKE' Filed Oct. 29, 1942 Oct. 24, 1944.

a l ATTORNEY EARLE E COOK Peienied ei.24, 1944 l y 2,361,087

UNITED S'IA'iiis,I Perf'ENToFFlcEv Earle s. cook, Wi1ki`nsburg`,ra.,assigne te* The Westinghouse Air Brake Company, vWilmerding, Pa., acorporation of Pennsylvania y vApplication October 29, 1942, Serial No.463,731 i 14 claims. ,(ci. iss- 195) This invention relates to railwayvehicle brake usua1 push rod 6. i' The outer end of the push rodapparatus and vmore particularly to variable load is. operativelyconnectedito the upper end offra brake apparatus of the type comprisinga brake vertically disposed brake= cylinder levery 'I, the rigging inwhich the leverage thereof may be lower end of the lever beingoperatively conautomatically Varied in accordance with varia-F55 nectedto one end of a longitudinally extending tions in they weight of theload on the vehicleso pull rod 8 leading to the other brake riggingele-` as to correspondingly vary the force with whichv ments (notshown), which actuate the usual fricthe brake is applied. ftion brakingelements into and out of braking en- An object of the invention is toprovide a novel gagement with the wheel and axle assemblies of variableload brake apparatus of the above men-m0 the vehicle truck. The lowerend of. the brake tioned type. e cylinder lever 1 is also connected tothe lower Another object of the invention is to provide a end of albrake hanger 9,"WhiCl1 hanger, et `its variable load brake apparatus ofthe above menupper end is connected to a bracket I0 carried tioned typewith means whereby the leverage of by the truck bolster I. the brakerigging is varied, only when the pres-m5 Rigidly attached to the bolsterI and extendsure of fluid in the brake system is being increased 'ineupwardly from-the lower side thereof is a Deir in charging, according tothe degree of relative of upwardly extending laterally Spaeed lugs I2,movement between a sprung and unsprung part only one of which'is shown,which carry a pin of the vehicle, and whereby at all other times the I4`upon which is vrockably lmounted 1 a lever- I5 means is unalected byrelative movement lne-$1120` which extends in -a direction transverselyof thel tween said parts. bolster. -At one side of'the'pin I4 the levercom- Other objects and advantages will appear in prises an arm I6 whichprojects beyond one side the following detailed description of theinvenpf the' truck bolster and at the other side the lever tion. v lcomprises'an arm II, the arm lebeing of greater Inthe accompanyingdrawing length thanvthearm I'I and terminating in the Fig, 1 is adiagrammatic view paruy in sec- -vicinity ofthe llongitudinal centerline of the tion, of a railway truck embodying the invention, bOlSiel iparts of the truck and of the brake rigging being The end of the arm `I6-carries a pin I8 which omitted to moreclearly illustrate certaindetails DaSSeS illiIOugll' 2 Slotted VOpening I9 fOrmed in of theinvention, 30 the brake cylinder lever 'I intermediate itsends.

Fig. 2 is a fragmentary sectional View taken on This Din SelVeS' aS afulerllm for the lever.

the line 2--2 of Fig. 1 to illustrate one of the The end of thefarm I-1is connected to the 11D- brake rigging adjusting elements and a part ofper end of a vertically extending rod 22 by means the truck with whichit is associated, of a pin 23, which rod extends-through a suitable Fig.3 is a p1an view of the adjusting element 1 35 opening -24 provided inthe bolster I and is Droand associated truck part illustrated in Fig. 2.vided at its lowerendvwith a spring-seat lin the As shown in Fig, 1 ofthe drawing, the variable form of a collar 25i di rload brake apparatusis applied to a railway ve- Interposed between the 'collar 25 andthelower hicle truck which may be `of the usual Well known side of' thebolster I- is a Spring 26 Which acts, all, construction having a truckbolster I, laterally all times,1to bias the rod 22 and thereby the armspaced side frames (not shown) which are rigid- I'I 0f the lever I5doWIiWaI'dIY- r ly carried in the usual manner by the wheel and The armI6 of the lever I5 is provided, at a axle assemblies (not shown), and.also having point intermediate tideL pins I4 and I3, `Wiill `el a springplank 2 which is xed to thetruck frames serrated or toothed lookingportiOn 01 Segment and upon which the usua1 truck bolster support- '.4528 which is adapted to be engaged by a correing springsS seat.`spondingly shaped toothed locking portion 29 The variable load brakeapparatus comprises which is carried at the upperend of a member "theusual brake cylinder device having a cylinder 30, which member, zasshown in the drawing, may

4 which maybe rigidly secured in any suitable be in the form of avertically disposed lever.

I manner to a xed `part of the vehicle truck, such The lower end of themember. 30 carries a 'pin for instance as the truck frame, or if desiredmay 3| on which there ls pivotally mounted an elebe secured to thetruckbolster. The brake cylinment in the form of a latch 32 which is-normallyder contains the usual piston having a hollow maintained in the positionshownin Fig. 1 of the push rod 5v which projects beyond the end of the`drawing by means of a leaf spring 33 which is cylinder and infwhich isrockablyrmounted the '55 vcarried by thememberabove the latch andpreferably adjacent thereto the member is pivotally mounted on a pin 34carried by a bracket 35 which is rigidly attached tothe bolster I andprojects downwardly and outwardly from the lower side thereof.

The member 30 is provided with a projection 36 to which one endof a coilspring 31 is attached, .theoppositeend of thespring. .being attachedto-a bracket .33 carriedl'byI and extending downwardly from the lowerside of the bolster I.

This spring tends, at all times, to maintain the chamber 62 is a spring68 which, at all times, acts v on the piston and tends to urge thepiston, piston member 3D in the position in which it is shown" land as aconsequence acts to yieldably maintain the locking portion 29inengagement withthe locking segment 28.

vided with a guide member 39 which lextends transverselyv of the..spring plank.l lSlidably' mounted in this guide member is a member. 40,

. lhaving at one end a wedged shaped portion 4 I the upper surface of:`the .member .being sloped rupwardly and outwardly: in vthe idirection of.the left .hand and :away 'from the :longitudinal centerline vofithefspring -plankand the lower surface :being iparallel with the.bottom 'wall .of ithe .guide mem- Vben-39.5'The guide member la, asbest shown in Eig. I2 .of thedrawing, may be .made integral with v .v'l5 The'upper side of the spring plank. '2 is prostem and slide valvetoward the position in which they are shown in Fig. 1 of the drawing.

The seat for the slide valve 61 is provided with a passage 10 which isin constant open communication with a pipe 1I. The pipe 1I is connectedto .the pipe `,53 vby means oi aflexible hose 12, whichhose accommodateslateral movement between the sprung and unsprung parts of the y vehicletruck.

It is obvious that any variation in the position :of k.the iulcrum pini8 with relation to the brake cylinderlever 1 Within the slotted openingI9 will t result in .a variation 'in the leverage ratio of the brakerigging'and thereby a variation in the braking power of the rigging.

the` spring .plank i2 and 4may .comprise a 'pair .of

. spaced-upwardly extending elements 4-2 :and l43.

Each orf-the elements -142 and 43 .are provided with a lshort inwardly:extend-ingfiange 44 adapted to iengage .a shoulder I45,"provided on'bottom of the member 40,fto prevent` upward movement '.ofjthe memberrelative to the spring plank.

' 1 The member.40;at its left hand fend, is provided 'with a verticallyientendingslot or recess 46 `in l which there"fzis-slidably.;.mounted :acollar 41. This collar is attached .to one end of an 'actuating roti '48vwhich extendsrthrough .a suitable open ended-slot F49 provided .in Vla,flange extending upwardly from one Vside-fof the `"spring plank '2 andati'ts 'opposite end is connected in .any suitable "manner'itoa piston15D. The'piston v'.il'l is con- '-tafined T aA'ey/linder -51 which Iislrigidly attached t6 the bracket 35 carried bythe truck bolster'.v

"' At-fone rside of the 1pistonf5 vthere is a chamber '5.2 which isconnectedto a pipe 53 by way-'of a passage 54.v `At the-opposite sidelofthe piston 50 "ther"i s` chamber 55" which is in -`constant :open`communi'ca-tion' with' the atmosphereby `way `of a passage '56,"Contained in'chamberli and interposed between and ioperatively :engagingthe `pistonfjand fthe-innerend wall of the chamber is a spring 51" whichtends, 'at all itimes, to urge the pistonfliyactuating rod 48 and member'40 to the Vposition infwhic'h they areshown in the drawing.

The actuating rod 48 is provided'with *a collar f'fcrlenlarged' portionavhich is'adapted vto be yrnoinei into and out-offengagement with thelatch 3! for fa purpose hereinafter described.

The apparatus AYfur-ther compri-ses ra changeover I 'l control valvedeviceA E!) `which may be attached in any suitable manner'to fthevehicle body or any other desired sprung part o f the vehicle -and maycomprises. kcasing in which there is mounted a pistenl; 'anchambefr {52,r which `is constantly connected At one side of the piston 6I there isthroughs/passage. ylafwith the atmosphere. At the'opposite `sideofthepiston there is avalve chapriber.@(54` ,which fis' constantly connectedthrough 'ja passage *and jpipe 65 with fthe usual `brake.pipe66.

i ,cqntameqinl 'yang chamber sa is 5a. suele valve 161 vyshfich isadaptedjto'be operated by apiston stern carried bythe piston 6I.

yContained "in decreased.

- Ii 4the Vfulcrum pin I8 is moved longitudinally ina direction awayfrom the brake cylinder the arm of the brake lever 1 to which the pushrod is conr'iected, will be correspondingly.lengthened so `that when:ythe brake cylinder .is operated, the power .transmitted bythe oppositeend ofthe lever to the pullrod 8 will be correspondingly increased. Ifthe pin is-rnovedirom the 'lower end ofthe slotted openingv inadirectiontoward the push rod-.6 the powertransmitted .tothe pull `rodwill be f -i Opration y Assuming the veiiiei, embodying the invention,to be empty and separated fromy a train, the

brakes on the vehicle 'released and the brake pipe oi .the vehicledeplete of fluidunder pressure.

Under these .conditions the several partsv of the .equipment will ybe intheposition fillustrated in the-drawing.

4.Now when thefemptyuvehicle -hisyplaced in a train, the -brakefpipewill of course'besupplied With uid under pressure, the `bralre pipethroughout the tra-in being fully charged tothe normal pressure. carriedrbeforethe tranis put in motion.

Fluid under pressurev` supplied to vthe .brake pipe flows therefromthrough pipe and passage `litito the valve chamber. `or' the.changeovercontrol .valve device 6B.' .With lthe changeover controlvalveslide v .alve -61 .in .its innermost position, -as

.-,shown inthe drawing, Ahuid .under @pressure .flows yfrom` the valvechamber 64 through passage 1U,

pipe 1I, iexible hose 12 and pipe 53 to chamber 5.2 .inthe-cylinder 5J.The changeover control valve piston and slide valvesremain in thisposition until' the pressure of iluid'in valve lchamber 64 has been.increased `s uiliciently, for instance to 'approximately thirty-*livepounds, toj-cause'the piston .and slide Valve to move outwardly against:the opposing pressure of the spring 68 kto a position in which theyslide valve 61 cuts oli' communiycation".between valve chamber 64 andl'passage 10 and #opens acommunication Abetween passage 1.0 and theatmosphere.

As the pressure of fluidsupplied'to chamber 52 .in the cylinderincreases, the piston 50 4and at- `tachedactuating rod 4B are caused tomoverlongitudinally in adirection toward the right, as viewed in thedrawing, against the opposing pressure of spring '51.

Y Movement of the rod '48 in this direction causes the collar orenlarged portionv carried `thereby and theattached member 40 tomove inthe same direction. As the rod continues to move ina di- "rectiontowardtheright-hand tl'ielcollar ".il'! engagesthe latch 3?.'Since'the'latch lis so constructed and arrangedfthat it cannotrockabout the pin`3l ina Acounter-clockwise direction relarocked moves thelocking portion 29 out of locku ing engagement with the teeth of thesegment 28 carried by the lever` I5, thereby unlocking the lever I5. Atthe same time,the continued movement of the rod 48 causes the wedgeshaped end 4| of the member 48 to pass under the collar 25 of the rod22. Cont-inued movement of the rod causes the upper or highest surfaceof the member 48, to pass underthe lower side of the collar A25 carriedby the lower end of the rod 22, and also causes the collar 58 carried bythe rod to pass under the latch 32.

Since the vehicle is empty the truck bolster I will be in its normalposition and as a consequence the lever I5 and rod 22 will be in theirnormal position, in which position they are shown in Fig. 1 of thedrawing. With the rod 22 thus positioned, the clearance between thelower side of the collar 25 at the end thereof and the upper side of thespring plank 2 is sufficient to permit movement of the member 48 betweenthe two without causing any upward movement of rod 22 inV opposition tothe spring 26, so that the fulcrum pin I8 carried at the outer end ofarm I6 of the lever I5, will remain positioned in the upper end of theslotted opening I9 in the brake cylinder lever 1.

At the time that the highest portion of the member 46 is 'moved rintothe vertical plane of the collar 25 or shortly thereafter the collar 58v n effect clockwise rotation of the member SI1-about the pivot pin 34.The member 38 as it is thus rocked causes the toothed locking portion 29to move into locking engagement with the toothed portion 28 of the leverI5, thereby locking the lever I5.

ASince as above mentioned there is no change in the position of the rod22 or thelever I5 at this time the fulcrum pin I8 will remain positionedin the upper end of the slotted opening I9 in the brake cylinder lever 1as shown.

When the pressure of fluid in chamber 64 of the changeover control valvedevice 68 has been increased to about 35 pounds, the piston 6I willmospheric passage 11. With this communication established, uid underpressurein chamber 52 of the cylinder 5I is quickly vented to theatmosphere, by way of passage 54, pipe 53, flexible hose 12, pipe 1 I,passage 18, cavity 16 in the slide valve 61 and atmospheric passage 11.Upon a reduction of pressure in chamber 52 due to this venting, thespring 51 causes the piston 58, member 40 and actuating rod 48 to movein a direction toward the left-hand into the position in which they areshown in Fig. 1 of the drawing.

As the rod 48 is thus moved, the collar 58 carried thereby engages androcks the latch 32 in a clockwise direction about pivot pin 3l againstthe opposing force of the leaf spring'33 thus permitting the collar 58to pass underthe member 38. When the collar has been moved in thisclirection into`the positionin which it is out of engagement'with thelatch, the leaf spring 33 will cause the latch to rock in acounter-clockwise ldirection about the pivot pin 3l into the position inwhich it is shown in the drawing. At

vthe time the collar 58clears the latch the membraking for the emptyvehicle.

It should here be mentioned that when the vehicle is in transit andthefulcrum pin I8 is locked in any position within the slotted opening I9by interengagement of the teeth on the locking portion 29 of? the member38 and the toothed portion 28of the lever I5, the member 48 will be outof the path ofvertical travel of the rod 22 and collar 25, so thatrelative movement between bolster I and spring plank 2 cannot causeshocks or heavy forces to be transmitted to the adjusting and lockingmembers thus effectively guarding these members against damage.

When it is desired to effect an application of the brakes fluiclunderpressure may be supplied to a pipe 19 in the'usual manner by a brakecontrolling valve device which may be of the AB or any other desiredtype; Fluid under pressure supplied topipe 18 ows to the brake cylinder4 -causing the brake cylinder piston, hollowpiston rod 5 and push rod 6to move in a direction toward the left-hand. As the push rod 6 moves ina direction toward the left-hand it actuates the brake cylinder lever 1to move the pull rod 8 to arated from a train' and the' brake pipe isdeplete of fluid under pressure, lading is placed on the body of thevehicle. Under the influence of the additional weight which the ladingimposes on the truck' bolster I, the bolster springs 3 will yield andpermit the bolster I to move downwardly relative to thev spring plank 2.s the bolster vI thus moves, the lever I5, rod 22 and bracket 3'5carrying theA member 38 andthe cylinder 5I move with it, thus reducingthe clearance distance between the under side of 'collar 25 and theupper surface of the spring plank 2.

It will be understood that the piston 58 and attached actuating rod 48move downwardly with the cylinder 5I and that the member 40 carried bythe spring plank 2 remains stationary, such relative movement betweenthe rod 48 and the member 48 being permitted by the sliding connectionbetween collar 41 at the outer end of the rod and the member 46.

Now when the loading of the vehicle is completed and the vehicle isplaced in a train and L the brake pipe is charged with iuid underpressure, locking portion 29, carried'by the member 38, is caused to bemoved out of locking engagement with the toothed portion 28 of the leverMI5,

and the member 48 is caused to be moved into the vertical plane of thecollar 25 at the lower end ofthe rod 22 in the same manner as beforedescribed in connection with the adjustment of the brake rigging forempty braking.

After the teeth of the locking portion 29 of the member 38 have beenmoved out of locking engagement with the toothed portion 28 of the leverI5, the sloping surface 18 of the member 48 will', due to the reducedclearance between the collar'25 and the spring plank, 'engage theA"underside of the collar 25. Now as the member 40 continues to move inthe direction toward the right-hand the member 40 causes the rod 22 to fcounter-clockwise directionabout the pin I4 thus causing the arm I1 ofthe lever I5, to move upwardly. This rocking movement of the lever I5-causes the arm I6 and thereby the fulcrum pin I8 atthe other side ofthe pin I4 to move downwardly, the pin I8 moving in the slotted openingI9 in the brake cylinder-lever 1. From this it will be understood thatthe fulcrum pin. I8 will be automatically positioned relative to thebrake cylinder lever 'I to provide for the degree of braking called forby the weight of the lading carried on the vehicle.

`With the full adjustment of the brake rigging accomplished thespring-31 `acts inthe manner hereinbefore described in connectionwithadjustment of the brake rigging for an empty vehicle to`automatically lock the rigging in its .load adjusted position. Now whenthe pressure in the brake pipe hasbeen increased to about 35 pounds themember 4,0 will be moved out of engagement with the collar 25 at thelower end of rod 22 in identically the `same manner as here- .inbeioredescribed in connection with the adjustment of the brake rigging for anempty vehicle. The fulcrum pin I8 will be maintained in its adjustedposition by the locked lever I until the brake pipe 66 is again depletedof iiuid under pressure.

Itwill be understood from the foregoing deiiuid under pressure toapproximately 35 pounds the brake rigging will be conditioned inaccordance with the load carried by the vehicle and will be locked inthis condition until such time as the pressure of fluid in the brakepipe of the iiuid pressure brake system is reduced to below `the settingof the changeover valve device 60. Y yHaving now described my invention,what I claim as new and desire to secure by Letters Patent, is:

1. In a vehicle variable load brake equipment of the type having a brakelever and means for actuating said lever, in combination, a fulcrum forsaid brake lever movable'relative to the lever inv-accordance withvariation in the `weight of the load carried by the vehicle, a controllever move upwardly against the opposing pressure of Yspring 26:

vscription that when the system is charged with AVing said control leverand thereby said fulcrum carried by a sprung part of the vehicle opera-Y tive to posiiton said fulcrum, locking means for locking said controllever and thereby said ful- ,crum in any selected position, and acombined lock. controlling and fulcrum positioning mech- .ing saidcontrol lever and thereby said iulcrum in any selected position, meansoperative to actuate said control lever, locking means for lockin anyselected position and movable to an unlocking position, and a combinedlock controlling and fulcrum positioning mechanism movable by fluidunder pressure to rst eiect operation of said locking means to saidunlocking position and` to then effect operation of said means toactuate said control lever. j

3. In a vehicle variable loadY brake equipment of the type having abrake lever and m'eans for actuating said lever, in combination, afulcrum for said brake lever movable relative to the lever in accordancewith variation in the weight of the load carried by the vehicle, acontrol lever pivotally carried by said sprung part of the vehicleoperatively connected at one end to said fulcrum and operative toposition said fulcrum, a vertically disposed member operativelyconnected tothe opposite end of said control lever and operative toactuate said control lever, locking means carried by the sprung part ofthe vehicle for locking said control lever and thereby said fulcrum inany selected position, means slidably mounted on an unsprung part of thevehicle for actuating said member, and means carried by the sprung partof the vehicle and operative by an increase in uid under pressure tofirst eiect voperation of said locking means to unlock said controllever and thereby said fulcrum and to them effect operation of saidfirst mentioned means.

4. In a vehicle variable load brake equipment of the type having a brakelever and means for actuating said lever, in combination,` a fulcrum forsaid brake lever movable relative to the lever in accordance withvariation in the weight of the load carried by the vehicle, ak controllever pivotally carried by said sprung part of the vehicle operativelyconnected at one end to said fulcrum and operative to position saidfulcrum, a vertically disposed member operatively connected to theopposite end of said control vlever and operative to actuate saidcontrol lever, locking means carried by the sprung part of the vehiclefor locking said control lever and thereby said fulcrum in any selectedposition, an' element slidably mounted on an unsprung part of thevehicle for actuating said member, and means carried by said sprung partof the vehicle and operative by an increase in fluid pressure to firsteffect operation of said locking means to unlock said control lever andthereby said fulcrum and to then effect operation .of said element, saidmeans comprising a movable abutment having an actuating rod operatively.connected to said element and an enlarged portion for effecting oper- Yation of said locking means. f

5. In a vehicle variable load brakeequipment of the type having a brakelever and means for actuating said lever, in combination, a fulcrum forsaid lever movable relative to the lever in accordance with Variationsin the weight of the` load carried by the vehicle, locking means forlocking said fulcrum in any selected position, and an element movable byuid under pressure for rst unlocking said fulcrum and for thenpositioning the fulcrum with relation to the lever, said elementcomprising a movable abutment, an actuating rod carried by saidabutment, a member for effecting movement of said fulcrum operativelyconnected to said rod and meanscarried by the rod for effectingoperation of said locking means.

6. In a vehicle variable load brake equipment of the type having a brakelever and meansfor load carried by the vehicle, locking means forlocking said fulcrum in any .selected position,V means movable by iiuidunder pressure forv firstl unlocking said fulcrum and for thenpositioning the fulcrum with relation to thelever, said meansvcomprising a member carried by al sprung portion of the vehicle andanother member carried by an unsprung portion of the vehicle, and meansoperatively connecting said member and other member. e

7. In a vehicle variable load brake equipment of the type having a brakelever and means for actuating said lever, in combination, a ulcrum forsaid lever movable relative to the lever in accordance with variationsin the Weight of the load carried by the vehicle, locking meansforlocking said fulcrum in any selected position, and means operative torst unlock said fulcrum and to then position said fulcrum, said meanscomprising a member carried by an unsprung part of the vehicle operativeto effect the positioning of said fulcrum and also comprising fluidpressure responsive means carried by a sprung part of the vehicleoperative to actuate said member.

8. In a vehicle vvariable load brake equipment of the type having abrake lever and means for actuating said lever, in combination, afulcrurri for said lever movable relative to the lever in accordancewith variationsin the Weight of the' load carried by the vehicle,locking means for locking said fulcrum in any selected position, a firstmember carried by a sprung part of the vehicle operative to unlock saidfulcrum, a second member carried by an unsprung part of the vehicleoperative to position said fulcrum, and' means responsive to an increasein fluid under pressure to first eiect operation of said first memberand to then effect operation of said second member.

9. In a vehicle variable load brake equipment of the type having a brakelever and means for actuating said lever, in combination, a fulcrum forsaid lever movable relative to the lever in accordance with variationsin the Weight of the load carried by the vehicle, locking means forlocking said fulcrum in any selected position, means operative to rstunlock said fulcrum and to then position said fulcrum, said meanscomprising a member carried by an unsprung part of the vehicle and iluidpressure responsive means carried by a sprung part of the vehicle foractuating said means, and a lost motion connection between said memberand said uid pressure responsive means to permit relative verticalmovement between the said means and fluid pressure responsive meansoccasioned by relative movement between said sprung and the unsprungparts of the vehicle.

10. In a vehicle variable load brake equipment of the type having abrake lever and a brake cylinder for actuating said lever, incombination,

a fulcrum for said lever movable relative to the lever in accordancewith variations in the Weight of the load carried by the vehicle, acontrol lever for shifting said fulcrurn, a toothed segment carried bysaid control lever, a lock member adapted to engage said toothed segmentfor locking said control lever and thereby said fulcrum in any selectedposition, means for effecting movement of said lock member into and outof engagement with said toothed segment, said means comprising a springfor eiecting movement of said lock member into engagement With saidtoothed segment and a movable labutment responsive to an increase influid under pressure for eiecting movement of said lock member` out oiengagement with said toothed segment, means operative. to position saidcontrol lever and thereby said` ulcrum, and fluid pressure responsivelmeans operative to control the. operation of the iir'st and secondmentioned means. y

11. In a variable load brake apparatus for a movable part, which movablepart is constructed and arranged forv vertical movement relative to thefixed part in res'po'nsepto` variations in the- I Weightimposed'thereon, in combination, a brake lever operatively connected atone end to a brake `member to be operated, a brake cylinder carried bysaid fixed part and operatively connected to the other end of said brakelever and operative to actuate the brake lever and thereby said member,a slotted opening in said brake lever extending longitudinally of thelever intermediate its ends, a fulcrum for said lever disposed in saidslotted opening, a control lever carried by said movable part operativeto shift said fulcrum along the brake lever, and means comprising amember carried by said xed part independently of said control lever andoperative to actuate the control lever.

12. In a variable load brake apparatus for a vehicle truck of the typehaving a fixed part and a movable part, Which movable part isconstructed and arranged for vertical movement relative to the iixedpartin response to variations in the weight imposed thereon, in combination,a brake lever operatively connected at one end to a brake member to beoperated, a brake cylinder carried by said xed part and operativelyconnected to the other end Of said brake lever and operative to actuatethe brake lever and thereby said member, a slotted opening in said brakelever extending longitudinally of the lever intermediate its ends, afulcrum for said lever disposed in said slotted opening, a control levercarried by said movable part operative to shift said fulcrum along thebrake lever, means comprising a member carried by said xed partindependently of said control lever and operative to actuate saidcontrol lever, and fluid pressure responsive means for controlling the.operation of said means.

13. In a variable load brake apparatus for a vehicle truck of the typehaving a fixed part and a movable part, which movable part isconstructed and arranged for vertical movement relative to the xed partin response to variations in the weight imposed thereon, in combination,a brake lever operatively connected at one end to a brake member to beoperated, a brake cylinder carried by said xed part and operativelyconnected to the other end of said brake lever and operative to actuatethe brake lever and thereby said member, a slotted opening in said brakelever extending longitudinally of the lever intermediate its ends, afulcrum for said lever disposed in said slotted opening, a control levercarried by said movable part operative to shift said fulcrum along thebrake lever, means comprising a'member carried by said fixed partindependently of said control lever and operative to actute said controllever, and means carried by said movable part operative to lock saidcontrol lever and thereby said fulcrum in any selected position.

14.- In a variable load brake apparatusfor aa vehicle truck of the typehaving a Xed partand- 6 assigne? relative to the xed part in responsetovariations'j in the Weight, imposed thereon, in combination,`

disposed in'said slotted opening, a control leverV carried by saidmovable part opera-tive to shift said fulcrum along the brake lever,locking means carried by said movable part and operative to lock saidcontrol lever and thereby'said fulcrum in any selected position, andv acombined lock controlling and fulcrum positioning mechanism 5 movable byuid under pressure to first unlock said fulcrum and to then effectmovement of said control lever to position said-fulcrum, said mechanismcomprising a uid pressure, responsivev abutment carried by said movablepart, a mem- 10 'Uber slidably mounted on said fixed part and meanskoperatively connecting said movable abutment to said member.

EARLE S. COOK.

